Documentation seems wrong about ULP FSM's JUMPR instruction (IDFGH-9574)

[agarof]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

There seems to have been an erroneous change in the ULP JUMPR instruction's documentation in v4.4.

In the ESP32 v4.3.4 documentation

Conditions LT, GE, LE and GT: 2 cycles to execute, 2 cycles to fetch next instruction
Conditions LE and GT are implemented in the assembler using one JUMPR instructions:
[...]
Conditions EQ is implemented in the assembler using two JUMPR instructions:

In the ESP32 v4.4.4 documentation

Conditions EQ, GT and LT: 2 cycles to execute, 2 cycles to fetch next instruction Conditions LE and GE are implemented in the assembler using two JUMPR instructions:

The ESP32 v5.0.1 documentation seems unchanged from v4.4.4.

Using a very minimal ulp program, I checked what code was generated for the ESP32 chip in both v4.3.4 and v5.0.1, which resulted in identical output for both versions.

    .text
    jumpr stop,1,CONDITION
stop:
    halt

Here are the code sections of the resulting bin.S files:
CONDITION = lt:

.byte 0x75, 0x6c, 0x70, 0x00, 0x0c, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x82
.byte 0x00, 0x00, 0x00, 0xb0

CONDITION = gt:

.byte 0x75, 0x6c, 0x70, 0x00, 0x0c, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x03, 0x82
.byte 0x00, 0x00, 0x00, 0xb0

CONDITION = le:

.byte 0x75, 0x6c, 0x70, 0x00, 0x0c, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x02, 0x82
.byte 0x00, 0x00, 0x00, 0xb0

CONDITION = ge:

.byte 0x75, 0x6c, 0x70, 0x00, 0x0c, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x03, 0x82
.byte 0x00, 0x00, 0x00, 0xb0

CONDITION = eq:

.byte 0x75, 0x6c, 0x70, 0x00, 0x0c, 0x00, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x05, 0x82
.byte 0x01, 0x00, 0x03, 0x82, 0x00, 0x00, 0x00, 0xb0

The eq version is one instruction (4 bytes) longer than the others, matching the v4.3.4 documentation.

[sudeep-mohanty]

Hi @agarof,
Thanks for bringing this discrepancy to our notice. Indeed, the description for JUMPR instruction for esp32 has been incorrect since v4.4. We will be updating the docs shortly and also back port the changes. Thank you!